Protective helmet



FIG. 1. is an upper a top perspective view of the a first embodiment of a protective helmet showing my new design;

FIG. 2. is a lower bottom perspective view thereof;

FIG. 3. is a front elevation view thereof;

FIG. 4. is a rear elevation view thereof;

FIG. 5. is a right left side elevation view thereof;

FIG. 6. is a left right side elevation view thereof;

FIG. 7. is a top plan view thereof; and,

FIG. 8 is a bottom plan view thereof.;

FIG. 9 is a top perspective view of a second embodiment of a protective helmet showing my new design;

FIG. 10 is a bottom perspective view thereof;

FIG. 11 is a front elevation view thereof;

FIG. 12 is a rear elevation view thereof;

FIG. 13 is a left side elevation view thereof;

FIG. 14 is a right side elevation view thereof;

FIG. 15 is a top plan view thereof; and,

FIG. 16 is a bottom plan view thereof.

The broken lines shown in the drawings illustrate portions of the protective helmet that form no part of the claimed design. 

CLAIM I claim the ornamental design for a protective helmet, as shown and described. 